1. Field of the Invention
The present invention is directed to a sturdy and flexible plastic tow hitch or bar device, and more particularly to a new and improved tow hitch for use with snowmobiles and sleds in the transport of cargo in the colder snowy regions of the world.
2. A typical dimensioned "FoxBow"
The U.S. Army Cold Regions Testing Center CRTC designed and fabricated tow hitch, that is, the present invention, and is identified under the common name of "FoxBow." The "FoxBow" is configurated to allow storage in the sled hull. The "FoxBow" was constructed, for the above testing, of three straps of light weight, high strength polyethylene, a product of the Poly-Hi Company of the Menasha Corp. The materials of the straps are 0.5 inch thickness cut to 2 inches width. The two main legs or traces of the tow bar are 55 inches in length and the counter-flexed center strap is 72 inches in length. The leg straps and center strap are drawn together with eight machine screws with appropriate nuts and washers. Likewise the snowmobile connection end of the assembly is sandwiched between the leg straps with three machine screws. The lunette type of hitch tip is 2 inch steel bar stock with a welded ring. The ends of the legs or traces that connect to a sled are reinforced with a steel bushing and connection is made with either quick release pins or machine screws. Using this towing bar multiple sleds can be towed tandem fashion by simply connecting with standard snap-links. Field repair of a "FoxBow" is easily accomplished if ever necessary, a pre-cut and drilled extra strap could be carried and installed with minimal skills and tools.
3. The Prior Art
a. The prior art discloses that the dynamic forces that are incurred when towing cargo laden sleds with snowmobiles has been destructive to the hitch points of the snowmobiles, the sleds, and the hitch tow bars themselves. This is compounded by the fact that when a snowmobile is moving over difficult terrain it is necessary to operate the snowmobile in an aggressive manner to maintain its momentum. Previously, sled hitches were constructed of metal, often fabricated with a coil spring type of a slip joint to absorb shock and stress. The metal hitches were overly heavy and did not serve their intended purposes well.
b. U.S. Pat. Nos. 3,721,454; 3,731,946; 4,353,563; and 4,856,799 disclose tow hitches or bars of the rigid metal type.
c. The present invention plastic hitch (FowBow) is light weight, tough, and provides a wide degree of flex effectively absorbing the major stresses that were previously imparted to the snowmobile and sled. The flexible nature of the counter-flexed "FoxBow" also facilitates connection to snowmobiles since perfect alignment is not necessary. This is especially important when performing these functions in deep snow.